[Media, Autoplay] Add UMA to record autoplay source

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index 7beecb9dd4be9a28665ac847fe9e6f45f67b085f..656fb5719b110fcb24eeb8f478c5aede6122fa3d 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -281,6 +281,16 @@ String preloadTypeToString(WebMediaPlayer::Preload preloadType)
     return String();
 }
 
+// These values are used for histograms. Do not reorder.
+enum AutoplaySource {
+    // Autoplay comes from HTMLMediaElement `autoplay` attribute.
+    AutoplaySourceAttribute = 0,
+    // Autoplay comes from `play()` method.
+    AutoplaySourceMethod = 1,
+    // This enum value must be last.
+    NumberOfAutoplaySources = 2,
+};
+
 } // anonymous namespace
 
 class HTMLMediaElement::AutoplayHelperClientImpl :
@@ -1618,6 +1628,7 @@ void HTMLMediaElement::setReadyState(ReadyState state)
 
         // Check for autoplay, and record metrics about it if needed.
         if (shouldAutoplay(RecordMetricsBehavior::DoRecord)) {
+            recordAutoplaySourceMetric(AutoplaySourceAttribute);
             // If the autoplay experiment says that it's okay to play now,
             // then don't require a user gesture.
             m_autoplayHelper->becameReadyToPlay();
@@ -2048,6 +2059,7 @@ Nullable<ExceptionCode> HTMLMediaElement::play()
 {
     DVLOG(MEDIA_LOG_LEVEL) << "play(" << (void*)this << ")";
 
+    recordAutoplaySourceMetric(AutoplaySourceMethod);

[mlamouri (slow - plz ping), 2016/06/08 12:30:03]

What we call "autoplay" is when there is no user gesture associated with the
play() method so I think this should be inside the "if
(!UserGestureIndicator::processingUserGesture())" block.

[Zhiqiang Zhang (Slow), 2016/06/08 12:55:14]

Done.

     m_autoplayHelper->playMethodCalled();
 
     if (!UserGestureIndicator::processingUserGesture()) {
@@ -3771,6 +3783,21 @@ EnumerationHistogram& HTMLMediaElement::showControlsHistogram() const
     return histogram;
 }
 
+void HTMLMediaElement::recordAutoplaySourceMetric(int source)
+{
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, videoHistogram, ("Blink.MediaElement.Autoplay.Source.Video", NumberOfAutoplaySources));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, mutedVideoHistogram, ("Blink.MediaElement.Autoplay.Source.Video.Muted", NumberOfAutoplaySources));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, audioHistogram, ("Blink.MediaElement.Autoplay.Source.Audio", NumberOfAutoplaySources));
+
+    if (isHTMLVideoElement()) {
+        videoHistogram.count(source);
+        if (muted())
+            mutedVideoHistogram.count(source);
+    } else {
+        audioHistogram.count(source);
+    }
+}
+
 void HTMLMediaElement::clearWeakMembers(Visitor* visitor)
 {
     if (!ThreadHeap::isHeapObjectAlive(m_audioSourceNode)) {